40 THE FOSSIL ECHINOIDEA 



series ; they are more or less discontinuous where the small crenulate and perforate 

 primaries exist. These are in slightly sunken scrobicules. Actinally the scrobicules 

 are in contact with the vertical ridge, which usually has a row of miliaries on it. On 

 either side, and abactinally to the scrobicule, is a raised ornamentation (on the base of 

 which rests the scrobicule) extending on either side, and marked with two or three 

 horizontal rows of miliaries. Towards the ambulacrum this ornamentation divides into 

 three ridges, which are continuous with the poriferous plates, and towards the median 

 line into two ridges, which unite with those of the tubercles above and below of the 

 neighbouring column. The ridges are narrow and miliary, and the spaces between 

 them, and on the bottom of which the coronal plates and distinct sutures are seen, are 

 elongate transversely, being crossed vertically by the raised ridge between the small 

 primaries. 



There are no penetrations of the test at the sutural angles. Actinally the spaces 

 between the ridges become deeper and smaller. 



Height of the test -^ inch, breadth at the ambitus -t^ inch. 



Locality. Hills east of Lynyan, from brown limestones. Eanikot series. Survey- 

 number G f |f , G fff-, G f |f . 



Illustrations of the Species in Plate IX. 



Fig. 4. Bictyopleurus Haimei, Duncan and Sladen : natural size. 

 5. Part of an ambulacrum, and interradial area : magnified. 



DiCTYOPLEUBUS Haimei, Buncan & Sladen, variety. 



There are some small specimens of this species in the brown limestone whence 

 the type was derived ; and they seem almost to unite the species Bictyopleurus costatus 

 and Bictyopleurus d' Archiaci. They would be considered young forms o£ Temnopleurus, 



Bictyopleurus Haimei, var. 



and might be classified with one of the species of that genus described by MM. 

 rt'Archiac and Jules Haime; but they are not members of the genus Temnopleurus. 

 The main distinction of these specimens from the type of Bictyopleurus Haimei is 

 that the bands of transverse raised ornamentation on the interradium are not so split up 

 and are higher; the bands unite along the median line by short processes, or their angles 



